Blockbuster Inc. knows the days of the movie rental store are numbered, as video downloads over the Internet slowly start to replace DVDs.

But knowing which way the wind is blowing doesn’t mean you can sail it. Blockbuster’s first box for playing Internet video on the TV doesn’t measure up to competing devices.

The company launched the MediaPoint player in November, selling it for $99 from its Web site. The first 25 movie rentals are free.

It’s a slim box made by 2Wire Inc. that connects to your TV and your home broadband line. Use the included remote to order a movie, and it starts downloading so you can begin watching after a few minutes.

It sounds pretty simple. But three similar devices I’ve tested in the past two years all are better than the MediaPoint. You’d think that the latecomer would be at least as good as the competition, since its creators have had time to learn from the others, but that’s not the case here.

On the MediaPoint, a movie will start playing after a minute or so, while it’s still downloading in the background. But it can’t be fast-forwarded or reversed until the download is completed, which takes up to an hour, depending on your connection speed. If you leave a downloading movie to go to the box’s main menu (maybe because you want to browse other selections) and then try to resume watching, the movie will start from the beginning, not from where you left off. Given that you can’t fast-forward, this is very annoying, although at least 2Wire is working on fixing it.

The on-screen interface is unattractive compared to the competition and looks blurry on a high-definition TV. It once crashed on me, forcing me to reboot the unit by unplugging it. Only some movies have previews, and those are shown in a tiny window. One preview was extremely loud, forcing me to dive for the volume control.

The remote is cluttered with cryptic buttons, very different from the simple, elegant controllers for the leading Internet TV boxes: Roku Inc.’s $99 Netflix Player, Apple Inc.’s $229-and-up Apple TV, and Vudu Inc.’s $299 Vudu.

As with its competitors, most of the movies available from Blockbuster Ondemand on the MediaPoint player are in standard definition, with some in high definition. The box doesn’t advertise which movies are in HD, and I didn’t stumble upon any. The other movies were close to DVD quality and looked acceptable on a large HDTV, though I found at least one that was presented in a smaller size than the others. It was surrounded by black fields on the screen. I was able to zoom in to make it fill the screen by using an unmarked button on the remote.

The MediaPoint is supposed to be able to connect to the Internet through an Ethernet cable or through a Wi-Fi router, but I couldn’t get the latter to work. 2Wire said that wasn’t typical.

The pricing model is also irritating, but this is something it shares with the Apple TV and the Vudu. You rent a movie for between $1.99 and $4.99. Once you start watching it, you have 24 hours to finish it. In other words, if you start watching “The Dark Knight” one evening, you pretty much have to watch it straight through. You won’t have time to finish it the next day, unless you start watching earlier in the day. Of course, you can always pay for it and download it again the next day. Just remember that you can’t fast-forward to find your place while you’re downloading the movie.

The ridiculous 24-hour rule, seemingly designed to keep people using DVDs, isn’t exactly Blockbuster’s fault. It’s imposed by the movie studios. But Netflix has managed to get its content licensed under a different system, which allows it to provide unlimited movie watching for as little as $9 a month. That means you can watch a new movie every night, or watch the same movie over and over if you want.

Blockbuster says that by licensing the movies as rentals, it has access to new movies within a month of their DVD release, sooner than Netflix. This is true to some extent: Last year’s blockbuster “The Dark Knight” isn’t available yet for Netflix streaming, though it is viewable through the MediaPoint player. But Netflix Inc. has a much deeper, more interesting library of about 12,000 online movies, compared to about 2,000 at Blockbuster Ondemand (both are expanding). And in any case, Roku is teaming with Amazon.com Inc. to offer rentals on the same terms as Blockbuster, in addition to the Netflix streaming service.

The MediaPoint player does have a few advantages over the Roku device. Because the Blockbuster unit downloads the movie, it’s able to offer the same image quality regardless of the speed of the broadband connection. Also, once the movie is downloaded, fast-forwarding or reversing is quick. The Vudu and Apple TV work the same way.

The Roku player doesn’t store movies, so the playback quality is directly related to the speed of the Internet connection. For the best quality, a fast DSL connection or a cable modem is necessary. Fast-forwarding and reversing is somewhat cumbersome.

The MediaPoint is also cheaper than the other downloading players, especially if you consider the included rentals.

All the same, this is not the box that’s going to make you give up DVDs. In movie terms, it’s “The Godfather: Part III” of Internet video devices: a sequel that doesn’t live up to the predecessors.